how to enable or disable a combo or dropdown when radio button is checked or unchecked using javascript

in this web programming tutorial you will learn that how to make a dropdown or combo enable or disable when a radio button is marked checked or unchecked.
copy and paste the below code in your section of the page.

and code for your asx.cs file

protected void Page_Load(object sender, EventArgs e)
    {
     if (!Page.IsPostBack)
        {
            radiobuttion1.Attributes.Add("onclick", "EnableDisableStatus()");
         }
     }